Artificial-stone product and process



July 7,1925.

J. w. LEDEBOER ARTIFICIAL STONE PRODUCT AND PROCESS Original yFiled Jan. 17, 1922 IN VEN TOR 'n A TTORNEYS, f

a citizen of the UnitedStates, residing atl vUNITED STATES PATENT OFFICE.

JOHN w. LEnRBOER, orl Ammin, PENNSYLVANIA, AssfeNOR ro AsBRsros SHINGLE, sLA'rR a sHEA'rHING COMPANY, A CORPORATION or PENNSYLVANIA;

A'RTIFICIALSTONE PRODUCT AND PROCESS.

Applicants inea January 1'7, 1922, seriaigN. 529,989. Renewed January 2s, 192s.

To all whom 'it may concern.'

vBe it known that I, JOHN W. LEDEBOER,

Ambler, -in the county of Montgomery and State of Pennsylvania, have invented certain new yLand useful Improvements in Artificial-Stone Products and Rrocesses, of which the following is a specication.

This invention relates to artificial stone products, and its object is to provide a composition ofehydraulic cement base which shall possess a maximum ,of strength and durability and at the sametime be convenient and economical to manufacture.

ln products of this character the'liydraulic cement is first worked up with a large'quantity of water and with a small proportion, say about 15% to 25% of the weight of the cement, offibrous material such as asbestos fibre, until the cement has assumed a stickly, `gluelike, or colloidal condition and has become thoroughly entangled by the fibres. The mixture is then worked up upon a paper making machine into sheets and subjected to pressure before the cement sets. Various attempts' have been made to reduce the cost of the ma.

.necting rod 14,' lever l5 and bearing rod terial'y by reducing the proportion of hydraulic cement and substituting therefor some'inert lling nfrateri'al.n of lower cost, but so far as "L am awareL these have all had the disadvantage that the resultant product is weak and brittle.

ln the accompanying drawings I have i'l lustrated in diagram a machine upon which my process can becarried out.

l first mix the hydraulic cement, asbestos fibre .and water in a beating engine in the usual manner, retaining, or even exceeding, the usual proportions of hydraulic cement and asbestos, until the cement is thoroughly colloided, 'or rendered sticky and gluelike, and entangled with the fibrous material. An example of proportions is 85% by weight of hydraulic cement and 15% of asbestos fibre. The mixture is then owed into a vat l, in which revolves ascreen roller 2" which in revolying picks up and deposits upon 'the endless felt belt 3 a .nlm Aof the wet/'hydraulic cement and asbestos fibre. .A suction box t removes surplus water ,from the mixture.\ Into a hopper 5 4is placed nely ground material, such as ,'ground scrap of the 'original material, i. e.

set and hardened hydraulic cement and asbestos fibre in the above given-proportions,

op other material of similar character. If

preferred more or less finely divided sand may be mixed with the material. A wire covered roller 6 feedsthe dry mixture to the lower. hopper I--where it is picked up by a revolving brush 8, from which it is .scraped "by aA scraper 9, and passing over the apron 10 the dry powdered material falls and sprinkles evenly upon the film of wetmaterial on thebelt. Various proportions Of the dry material with respect to the wet material may be used according to conand the cement allowed to set. -Sucient pressure to form the sheet is impartedl to the cylinder l1 by its weight and by the weight-l2 acting through the lever i3, con- 16. @ther rolls l? and 18 may be employed terial and water until the cement has become sticky and entangled ,with fibre, then forming the wet mixture f in a sheet, then sprinkling the sheet with finely divided material, then building'up said sheet into a plurality yof thicknesses, then subjecting the mixture to pressure, and then allowing the "hydraulic Vcement to consists in first l0@ 2. The process which working up hydraulie cement, 'fibrous niaterial and water until the 'cement has loecome sticky and entangled with fibre, then formin the wet mixture in a sheet, then sprinkling the sheet with finely divided ma- 105 terial containing nely divided silica, then buildingl up said )sheet into a pluralitylof thicknesses, thensubjecting the 'mixture to pressure, and then allowing the hydraulic cement Vto set.

3. The process which consists in first r Working up hydraulic cement, fibrous material and Water until the cement 4has become sticky and entangled with fibre, then fol-min the Wet mixture in a: sheet, then sprinkling the sheet with finely divided ma terial comprising finel divided hydraulic cement, fibrous materia and silica, then subjecting the mixture to pressure, and then allowing the hydraulic cement to set.

4. The process which' consists in first working up hydraulic cement, fibrous :ma-

terial and Water until the cement has become sticky and entangled with fibre, then forming the wet mixture in a sheet, vthen sprinkling the sheet with finely divided vinert material in the proportion of .approximately one-third inert material to twofthirds Wet mixture, then building up said sheet into a plurality of thicknesses, then subjecting' the mixture to pressure, and .then allowing the hydraulic cement to set.

5. The process which consists in first working up hydraulic cement, fibrous material and water until the cement has become sticky and entangled with fibre, vthen forming the Wet mixture in a sheet, then sprinkling the sheet with finely divided inert material, building up the said sheet in layers, subjecting the mass to pressure, and then allowing the hydraulic cement to set.

6. Al productcomprising a series of layers of hydraulic cement entangled with fibrous material and alternatingtwith a series of layers of finely divided'inert material, the Whole being subjected to pressure before the hydraulic cement is set.

' JOHN W. LEDEBOER. 

